Who out there has heard that you are supposed to drink eight–eight ounce glasses of water a day? What about the one where you take your weight, divide it in half, and that’s how many ounces of H2O you’re supposed to get? Or what about the thought that you don’t even need to drink water because you can get it all from your food?

The truth is: none of these are right. Or at the very least, none of these are right for everyone.

Hydration recommendations can be a confusing land to navigate. That’s because it isn’t as simple as one baseline suggestion for everyone. The amount of water you need to drink in a day depends on your weight, sex, activity level, diet and even where you live.

The Institute of Medicine has determined that for an average-sized healthy man living in a temperate climate with a moderate activity expenditure has an Adequate Intake (AI) level of fluid of about 3 liters per day (it’s 2.2 liters for women).

So what does that mean in English? Well, if you are a guy, who is a healthy weight, does an average amount of exercise and lives in a mild to moderate climate, you need a minimum of three liters of total fluid in a day. And fluid means more than just straight up tap water. Juices, milk, and even coffee can count to your total. But really, plain water is your best choice because it is calorie free, doesn’t spike your blood sugar and doesn’t have other chemicals that affect your body (think: caffeine).

So what if you aren’t an average-sized person living in an average climate with average energy expenditure? Well, chances are, you need even more water. Here are a few factors that might up your need:

• Exercise. Love a good sweat session? If so, you need to be drinking more water to replace that sweat. Also keep in mind that you not only lose water, but electrolytes, too during heavy exercise. Sports replacement drinks (I love the dissolvable tablets without added sugar) are a great way to keep your electrolyte balance intact.
• Climate and altitude. Where you live can greatly impact how much water you need. If you live in a particularly hot and humid part of the world, you’ll need to stay hydrated more than someone that lives in a cooler climate. Live up in the mountains? High altitude can trigger symptoms of dehydration. Folks who live in high altitude areas need to drink more than the standard AI.
• Health conditions. If you are feeling under the weather, you’ll need to be downing more water than usual to keep your body in good condition to get healthy. It's especially important to drink more than the AI if you have a fever or diarrhea.
• Pregnancy and breastfeeding. Not only are you eating for two, but you’re also hydrating for two. It’s important for pregnant and breastfeeding women to drink more than the AI level of fluid.

If all of this sounds too complicated, you’re in luck, because unless you have a medical condition that otherwise prevents it, your body gives you all the tools you need to determine your proper hydration levels. If you are drinking enough during the day to rarely feel thirsty, you are in good shape. Also, check in the bathroom, if your urine is colorless or very pale yellow, you are on the right path. Sometimes, just keeping an eye on your own body and how you feel is better than any recommendation you could read from even the most reliable source.

Do you stay adequately hydrated during the day? How much water do you tend to drink?

photo credit: lululemon athletica